PHP：如何从递归函数返回值的计数器？

Question

function count($array){ 

    $counter=0;
    foreach($array as $key=>$value){ 
    if(is_array($value)){ 
            count($value); 
        }else{
            if(strcmp($value, "Hi") == 0){
                $counter++;
            }
        }
    }
}

$arrays = array("Hi", "a", "Hi", "b", "c", array("c", "Hi", array("Hi"), "d"));

If I call count($arrays); I want to print 4 in this case.
But my code keeps printing 0. It seems it does not return counter of "Hi" properly but I have no idea.

Answer 1

count() is a built-in function of PHP, better if you change the name:

function myRecursiveCount($array, $needle = "Hi"){ 
   $counter=0;
   foreach($array as $value){ 
     if(is_array($value)){ 
       $counter += myRecursiveCount($value); 
     } else if ($value === $needle){
       $counter++;  
     }
   }
   return $counter;
}

$inputs = array("Hi", "a", "Hi", "b", "c", array("c", "Hi", array("Hi"), "d"));
echo myRecursiveCount($inputs); // Prints 4

You need two edits:

• the function should return the $counter;
• in the recursive call you should append the result: $counter += f();.

I have also applied two optional improvements:

• you don't need to populate the variable $key as you don't need it
• to compare two strings you can simply use == comparison operator (strcmp feels so old)

Live on codepad: http://codepad.org/ATiKV09d